1. Field
The following description relates to a bump including a diffusion bather bi-layer, and a manufacturing method thereof, and, for example, to a bump including a diffusion barrier bi-layer in a semiconductor 3D stacking process with a excellent mechanical intensity and reduced disintegration of a nickel-phosphorus diffusion barrier layer during a bonding process, and a method for manufacturing the same. The diffusion barrier bi-layer of the bump may be formed of a copper layer and a nickel-phosphorus alloy layer, for instance.
2. Description of Related Art
In a semiconductor 3D stacking process, the reliability of a bonding material used to connect upper and lower chips is important for obtaining a reliable bump.
In conventional bumps, a solder material 200 is deposited directly on a conductive layer 100, as in a bump 1000 illustrated in FIG. 1, or a Ni—P diffusion barrier 110 layer is disposed between a conductive layer 100 and a solder material 200, as in a bump 2000 illustrated in FIG. 2.
However, the use of a Ni—P Under-Bump Metallization (UBM) layer 110 having a thickness of 5-10 μm may not be suitable for use in a packaging bonding of the conventional solder-ball manufacturing method. The Ni—P UBM layer may be too thick for use in a semiconductor 3D stacking process where volume reduction is an issue.
Furthermore, a method of excluding a Ni—P layer 110, and bonding the copper of the conducive layer 100 directly with a solder material 200 also may cause a problem, since an intense interaction between the copper and the solder material 200 may significantly decrease the reliability of the bump 1000.
Accordingly, it is desirable to develop a diffusion barrier layer for a bump that suppresses an interaction between copper and solder material while maintaining a small volume during a semiconductor 3D stacking process.